CHARACTERIZATION OF THE GENE ENCODING THE MOST ABUNDANT INVITRO TRANSLATION PRODUCT FROM VIRUS-INFECTED CHLORELLA-LIKE ALGAE

The gene (33kDa) encoding a 33-kDa peptide from Chlorella virus, PBCV-1, was cloned and sequenced. This gene encodes the most abundant in vitro translation product synthesized from viral mRNAs isolated beginning at 20 min post-infection. The message persisted throughout the remainder of the viral life cycle. An open reading frame (ORF) of 717 bp, which encodes a polypeptide of 238 amino acids with a predicted M(r) or 26613, was found on a 2752-bp cloned fragment from PBCV-1 HindIII restriction fragment 9. Transcriptional analysis of this ORF indicated that it was expressed both early and late, and as the viral life cycle progressed, the mRNA increased in size and abundance. Three other ORFs were also found; the largest of which (741 bp) hybridized to a low-abundance transcript which would encode a polypeptide with a predicted M(r) of 27 854.